| Emergent Manufacturing Solutions, LLC Milling, Turning · ISO 9001, AS9100, ITAR, ISO 13485, IATF 16949 | Loves Park, IL | MillingTurning | ISO 9001, AS9100, ITAR, ISO 13485, IATF 16949 |
| Eton Machine Company Limited Milling, Turning, Swiss, Grinding, Assembly · ISO 9001 | Elgin, IL | MillingTurningSwissGrindingAssembly | ISO 9001 |
| Evergreen Machining Services Milling, Welding, Stamping, Metal AM · ISO 9001 | Rockford, IL | MillingWeldingStampingMetal AM | ISO 9001 |
| Frey & Weiss Precision Machining Inc Milling, Turning, Grinding, Assembly · ISO 9001 | Wood Dale, IL | MillingTurningGrindingAssembly | ISO 9001 |
| NKP Metals LLC Waterjet, Welding | Chicago, IL | WaterjetWelding | - |
| Pegasus Mfg Inc Milling, Turning, Metal AM · ISO 9001, AS9100 | Galesburg, IL | MillingTurningMetal AM | ISO 9001, AS9100 |
| Saporito Finishing Co Welding, Finishing · NADCAP | Cicero, IL | WeldingFinishing | NADCAP |
| Stanley Spring and Stamping Corp Laser, Bending, Stamping, Assembly | Chicago, IL | LaserBendingStampingAssembly | - |
| The Bennu Group Inc Milling, Turning, Waterjet, Welding, Finishing · ISO 9001 | South Holland, IL | MillingTurningWaterjetWeldingFinishing | ISO 9001 |
| 360 Machine Shop Milling, Turning, Laser, Welding, Metal AM | Bloomington, IL | MillingTurningLaserWeldingMetal AM | - |
| Anchor-Harvey Components LLC Milling, Forging, Finishing · ISO 9001, AS9100 | Freeport, IL | MillingForgingFinishing | ISO 9001, AS9100 |
| Astoria Wire Products Inc Milling, Laser, Punching, Bending, Welding | Bedford Park, IL | MillingLaserPunchingBendingWelding | - |
| Atlas Tool & Die Works Inc Turning, Laser, Waterjet, Welding, Stamping, EDM, Assembly | Lyons, IL | TurningLaserWaterjetWeldingStampingEDMAssembly | - |
| Bennett Metal Products Inc Milling, Turning, Waterjet, Welding · ISO 9001, ITAR | Mount Vernon, IL | MillingTurningWaterjetWelding | ISO 9001, ITAR |
| Betts Precision, Inc Milling, Turning, EDM, Grinding · AS9100, ISO 13485 | Alsip, IL | MillingTurningEDMGrinding | AS9100, ISO 13485 |
| CM Fabrication, LLC Milling, Laser, Welding, Finishing | Sycamore, IL | MillingLaserWeldingFinishing | - |
| Custom Laser Works LLC Laser, Bending, Welding | Addison, IL | LaserBendingWelding | - |
| Demco Products Milling, Turning, Swiss, Finishing, Assembly · ISO 9001 | Oak Lawn, IL | MillingTurningSwissFinishingAssembly | ISO 9001 |
| Foster Works LLC Laser, Punching, Bending, Welding, Stamping, Finishing | Chicago, IL | LaserPunchingBendingWeldingStampingFinishing | - |
| Hy-Tek Manufacturing Co., Inc Milling, Turning, Assembly · ISO 9001 | Sugar Grove, IL | MillingTurningAssembly | ISO 9001 |
| Jacksonville Machine, Inc Milling, Turning, Welding, Grinding · ISO 9001 | Jacksonville, IL | MillingTurningWeldingGrinding | ISO 9001 |
| Kadon Precision Machining Turning · ISO 9001 | Rockford, IL | Turning | ISO 9001 |
| Kocsis Brothers Machine Company Welding, Assembly | Alsip, IL | WeldingAssembly | - |
| Laystrom Manufacturing Company Bending, Laser, Welding | Chicago, IL | BendingLaserWelding | - |
| Morgan Bronze Products, Inc Turning, Welding, Casting · ISO 9001 | Lake Zurich, IL | TurningWeldingCasting | ISO 9001 |
| Saliba Industries Milling, Turning, Grinding | Waukegan, IL | MillingTurningGrinding | - |
| Smith & Richardson Manufacturing Co Milling, Stamping, Casting | Geneva, IL | MillingStampingCasting | - |
| Stuecklen Manufacturing Co Bending, Finishing | Franklin Park, IL | BendingFinishing | - |
| Surface Finishes Welding, Grinding · ITAR | Addison, IL | WeldingGrinding | ITAR |
| Sycamore Precision, Inc Milling, Casting, Finishing | Genoa, IL | MillingCastingFinishing | - |
| Thomason Machine Works Inc Milling, Turning, EDM · ISO 9001 | Rockford, IL | MillingTurningEDM | ISO 9001 |
| Waltz Brothers, Inc Turning, Grinding · ISO 9001 | Wheeling, IL | TurningGrinding | ISO 9001 |
| Accumation Swiss Turning, Swiss · ISO 9001 | Crystal Lake, IL | TurningSwiss | ISO 9001 |
| Aztec Plastic Company Welding, Stamping, Grinding, Finishing, Assembly | Chicago, IL | WeldingStampingGrindingFinishingAssembly | - |
| B T M Industries Inc Milling, Turning, Welding, Casting, Grinding | Woodstock, IL | MillingTurningWeldingCastingGrinding | - |
| Chicago Metal Supply & Fabrication Inc Bending, Welding, Waterjet, Stamping | Chicago, IL | BendingWeldingWaterjetStamping | - |
| Deines-Nitz Solutions, LLC Milling, Finishing | Erie, IL | MillingFinishing | - |
| Faspro Technologies, Inc Laser, Stamping, Assembly | Arlington Heights, IL | LaserStampingAssembly | - |
| G & Z Industries Inc Casting, EDM · ISO 9001, ITAR | Wheeling, IL | CastingEDM | ISO 9001, ITAR |
| Jem Custom Products, Inc Milling, Finishing | Wauconda, IL | MillingFinishing | - |
| Murphy Machine Products, Inc Milling, Turning, Swiss, Grinding, Finishing · ISO 9001 | Wood Dale, IL | MillingTurningSwissGrindingFinishing | ISO 9001 |
| Odin Fabrication, Inc Laser, Punching, Welding, Finishing | Elburn, IL | LaserPunchingWeldingFinishing | - |
| Panek Precision Products LLC Milling, Turning, Stamping, Grinding, Finishing, Assembly · ITAR | Northbrook, IL | MillingTurningStampingGrindingFinishingAssembly | ITAR |
| Quality Metal Products Inc Milling, Turning, Finishing | Peoria, IL | MillingTurningFinishing | - |
| R C Industries Inc Finishing | Chicago, IL | Finishing | - |
| Abbate Screw Products Inc Milling, Swiss, Grinding | Roselle, IL | MillingSwissGrinding | - |
| Ability Metal Company Milling, Turning, Assembly | Elk Grove Village, IL | MillingTurningAssembly | - |
| American Machine Tools Co. Milling, Turning, Bending | Chicago, IL | MillingTurningBending | - |
| Calisota Parts, LLC Milling, Waterjet, Stamping, EDM | Frankfort, IL | MillingWaterjetStampingEDM | - |
| Cast Technologies Inc Casting | Peoria, IL | Casting | - |